The first is that faith-based discourse will cause religious views to be legally imposed on secular citizens. To see why this is misconceived, just consider the nature of democratic lawmaking. When parliament passes any law it is necessarily imposing a particular view on its citizens. The issue is not whether citizens should be imposed on by law but what should be imposed on them.

Many laws rest on definite moral standpoints; they are not simply technical administrative devices. They assume a specific view on some important human good or value. This is as true of so-called progressive laws, such as those proscribing race or sex discrimination or curbing excessive banking bonuses, as it is of so-called conservative laws opposing euthanasia or resisting easy divorce.

And while the moral standpoint behind a law may sometimes be widely shared, in many cases it is deeply controversial. More and more laws today leave significant numbers of citizens feeling that their deepest convictions have been ignored and some alien moral standpoint "imposed" on them. If some future government builds a third runway at Heathrow I will experience having been imposed on by a secularist moral viewpoint I profoundly reject – an irrational faith in endless economic growth held in defiance of scientific findings about climate change. That wouldn't make me want to exclude that secularist viewpoint from political debate, only argue more strongly against it.

The second objection is that faith-based arguments are unintelligible or inaccessible to most citizens, whereas secularist moral arguments can be embraced by everyone. But given that polls suggest over 70% of British people hold to some kind of religious faith, it seems quite likely that most will be able to make some sense of political arguments appealing to faith. When Desmond Tutu called for the abolition of apartheid legislation because every human being is "made in the image of God", I don't recall secularists scratching their head in puzzlement.

The third objection – the weakest – is that religious faith is just irrational and so can never be the basis of democratic reasoning. The objection comes in cruder positivist forms, such as "belief in God is like belief in invisible unicorns": if you can't experience it through the evidence of the five senses, it doesn't exist. This 19th-century view was discredited ages ago by philosophers of science who recognised that human experience is a rich and complex phenomenon yielding reliable knowledge through many routes. There are more sophisticated versions, but all of them fail to see that faith is not an alternative to reasoning but its precondition. All chains of reasoning get going on the basis of presuppositions which cannot themselves be proved rationally. The objection also fails to see that secular humanism is itself a faith standpoint, resting on similarly unprovable assumptions such as the primacy of rational autonomy, the supremacy of natural scientific knowledge, or the self-creation of the cosmos.

If we want a truly pluralistic democracy which builds consensus by honouring difference rather than suppressing it, we should ensure that democratic debate remains open to as many moral and faith-based standpoints as possible. In a pluralist democracy pretty much everyone at some point is going to feel imposed on by some legislated moral standpoint they deeply repudiate. So for exclusivists to single out just one class of moral standpoints – religious ones – as unacceptable cannot be justified.